Hot or cold foods, particularly items which are intended for later consumption, are frequently transported, and temporarily stored in cardboard or in chipboard boxes, the size of which is matched roughly to the maximum dimension of the items to be packaged. The shape of the box often is different from that of the item, i.e., the box is usually square, although the item is round. The cardboard boxes are usually shipped flat, to be erected on the spot, thus saving in storage and shipping space. The boxes are not intended for re-use, and are therefore made of a thin and inexpensive paper material, just strong enough to provide some protection of the contents from ambient influences, such as dust, dirt and, of course, heat exchange. Such boxes frequently, when erected, take up a volume which is substantially in excess of that required by the food items themselves. Their fragile and flimsy nature, even when erected, contributes little to the support of the food contents which may require further support on trays or carriers, lest the contents break. This is particularly true for large items based on pie crusts, such as hot pizzas, cold desserts including pie crusts and the like. It has previously been proposed (see, for example, U.S. Pat. No. 2,845,104) to make carriers for food items of relatively hinged parts, so that a chamber is formed within which small food items, such as hamburgers and the like can be carried, the hinged portions being folded together and locked along the rim edges to provide a substantially closed container. In food preparation establishments, storage space for containers to be handed to customers, and thus used at a substantial rate, is usually at a premium; further, economics dictate that the cost of the containers (which are customarily discarded after use) be small; yet they should be sturdy and provide the required mechanical and environmental protection while additionally having thermal insulating properties.
It is an object of the present invention to provide a thermally insulated food container, for temporary use, which is inexpensive and requires but little space for storage and shipping, which is light-weight, and yet sturdy.